Airplane



March 26, 1946. w M 2,397,189

AIRPLANE Filed Sept. 7, 1942 DAVID W. MMN

INVENTOR.

ditor gare employed Patented Mar. 26, 1946 UNITE o STATES PATTE NT? OFFICE AIRPLANE David W; Main, Denver; Colo. ApplicatlonSeptember 7, 1942, seria1 No. 457,623 f1 Claim; (01. 244-99)- This invention relates-to improvements in air-v planes and has referencemore particularly to animproved propeller mechanism; I With the'ore dinary type ofairplanes employing I tractor :propellers, considerable difliculty is rexperienced in taking of! from the ground and with such airplanes a long'airfield is required inorder that sumcientspeed can be developed to create the necessary lifting force. i

It is one f the objects of" this invention to provide "an airplane with-propellers that shall be efi ective for producing a lifting, as-well as a tractive, force, whereby the'speed necessary to raise an airship' from'th'e ground can be reduced inan appreciable amount, thereby making it possible to take offfrom shorter airfields. a

Another object of this 'invention is to produce an airplane having propellers positioned-alon the front edges of'the wings, such propellers being rotatable about axes substantially parallel with the axis of the wings-and provided-- with radial=vanes which engage the air so as-to produce both a lifting and a tractive force when rotated'at high speeds in such a direction that the i vanes move rearwardly -hbelow the axis of rotation; l

In order to describe: the invention so that its construction 'andmode of operation-can-be readily understood reference will beihad to ithe accompanying drawing in which one lspecific -embodi-' ment of the invention has been illustrated, and in which? I l Figure-.1 is a perspective-viewshowing la portion of an airplane in which the wings are provided'with propellers of rthe type to whichrthis invention relates; v

FigureVZ is a front: view of the airship shown in-Figurel looking intheadirection' of arrow 2 and shows the construction' to a Slightly-larger scale Figure 3 isa section taken along' line '33, Figure 1 and showsthe position of the'propeller with respect to a crosssection of the wing;

Figure 4 is an enlarged-cross sectional view taken along-llne"4-4;Figure' 1, and shows a slightly modified form of propeller and illustrates in greater detail the construction;

Figure 5 is a top plan view of-the rear end of a plane showing the transverse stabilizing'vanes thereof Figure 6 is a top plan view of the modified form ofairship' in' which a lurality ofpa'irs fof Wi s Figure 7 is a side elevation of the'iairplane' shown in Figure 6; g Figure 8 showsa modified form" of: propeller constructiomand Figure Qshows an oscillating form of propeller; In the drawing referencenumeral l0:'desigates the fuselage of an airplane. The exact construction of the fuselage .has-notbeemshovin becauseit is independent of theinvention covered by this application. v

I The ordinary motorusually provided for airships, has been designated by reference numeral H and the tractorpropeller by numeral Il -The engine and propeller have been shown'diag-rammatically a they are of usual construction and their relation to an airship is well kn0wn-.:- e

Extending laterally from the fuselageare wings 13 one pair being shown in Figures 1: and 2. l The wings-may beof the usual construction and have a cross section like that shown inFigure'S. The

diagonals 14 indicate the truss members usually provideoli airplane Wings. I

The wings differ from the ordinary Wing-s1 in this that the frontedges are providedwith elongated openings I 5 in which are positioned-clon gated propellers whosehubs have been designated by reference; numerals -I 6. Extending radially from the v hubs are blades 1 1; These blades-pray be longitudinally straightand have the greater portion of their areas lying in planes-containing the axis of rotation, Or} they may-be-helical-as shown in Figures 1 and 2, the latter-being preferable A cross section-of the blades'may be like that shown in Figure 4 in which: the-portion nearestthe'hub is radially straight and-terminates in'a forwardly inclined edgel 8. -The center of curvature of the inclined edges lies to-the 'i'rontof the blade when the edge is at the-top and to the rear when the blade is at the bottom,

as can be clearly shown from Figure 4. In Figure 3, the blades have been shown arcuate and curved about the centers 0. Each -wing has a portion of its front edge'cut away so as toprovide access to the space occupied by the propeller. ate metal wall 19 extendsupwar'dly from-the lower Wall 20 of the wing as shown in Figure 4 and an arcuatewall 2| "has its lower and rear wardly positioned edge overlapping the wall 18 and extends upwardly to a point indicated-by reference numeral 22'. The lower rear edgeaof the wall 2| is provided with gear teeth ziithat are engaged by a pinion 24-which is-secured to a shaft-.15 that can berbtated-bY-suitable means accessibleto the pilot. The curved or arcuate Anarcu- 1 wall 2: is provided with a plurality of openings 26 through which air may escape as indicated by arrows 21. The top wall of the wing is provided with a plurality of openings 28 formed by slitting the material and bending a, portion thereof upwardly as indicated by reference numeral 29. The arrows 30 designate the direction and position of the air stream that passes over the wing. V

V, The area between the arrows 30 and the top of the wing, which area has been designated by referencelnumer'al 3|, is greatly rarified, ap-

proaching in some cases quite close to a vacuum.

Due to the low pressure in area 3| the air thrown outwardly from the rotating propeller, as indi-H cated by arrows 29, will pass outwardly in the direction of arrow 28, thereby reducing the air,

density between the propeller blades, if' desired. Each propeller is secured toa drive' shaft blades through a greater arc and it will therefore prevent air from coming into contact with the blades until they have reached such a position that no retarding force component is created. V,

In landing it may be desirable to rotate the wall 2i in a clockwise direction so as to neu-' tralize to some extent the tractiveeifort of the blades 11. By adjusting the rotary position of wall 2|, the effect produced by the rotating propeller can be modified so aspto" produ ce effects most suitable for the conditions under which the airplane is operating.-

' The invention has been illustrated in connection with the airplane having one pair of'wings' as is most usual. It is possible, however and sometimes desirable, to provide an airplane fuselage like that designated by Na in Figures 6 and which has been designated by reference numeral 32 in Figure 4. The shaft 32 is rotated in the direction of the arrow in Figure 1 and in a counterclockwise direction when viewed as in Figures 3 and 4, by power from the engine H. This power is transmitted to the 1 shaft by any suitable motion transmitting means'and as il lustrative of such means shaft 32 in Figure 1, has been shown as provided with a gear wheel 33 that is in mesh with a gearwheel 34 carried on shaft 35. The motor shaft 36 is provided with a bevel gear 31 that cooperates with a pinion 38.

cated in therecesses I5 of the blades.

- Wewill now refer to Figure 4, from which it will be seen that the blades I! are rotated in a counterclockwise direction. When the blades arr'ive at theend of wall 21, which has been designated by reference numeral 22,-air will enter the space between two adjacent blades and since these are rotatingat a high velocity, their reaction when striking the vertically stationary air currents will be to produce aforce having a component tending to lift the "plane. These components of force have been designated, for the pur pose of illustration, in- Figure 4, byreference nu meral 39. As the blade-moves downwardly, thev lifting component will increase,becoming maximumwhen the blade is in a horizontal position. The" lifting component will then' decrease and another force will beproduced which tends to move'the airship forwardly; The effect of the rapidly rotating longitudinally extending propel-lers is therefore toproduce a lifting'foroe and,

in'addition a-tractive force that supplements the. 55

tractive force produced by the propeller l2. 7

It is evident'that during the time that the blades move from the lower end of the arcuate wa1l'l9 to the forward and upper end of wall 2|, they will exert no appreciable force tending to, movethe airship in any direction, with the ex- -ception of the tractive forces produced by the flowof air through the openings as indicated by arrows 21. The centrifugal forces exerted by the rotating propeller, aswell as the suction due 1 Whenever the engine Operates to turn propeller 12, it will also rotate the propellers loto the 'rarified area above the wing tends to ex- 'haust theair from between the blades of the propeller so that, when the latter movev beyond the edge 22, the air'in which the ship is moving 'will rush into the 'rarified space in suflicien't volume to produce an'appreciable resistance by its inertia effected."

' 'It is evident that if thecylindrical wall 2! is? rotated in'a counterclockwise direction from the position shown in Figure 14," it I will shield the 7, with a plurality of pairs of Wings such as have beendesignated by reference numerals [3a, and' tolprovide each. Wi withiai propeller, like that shown in-Figures;.;l*to ,4.- gltgis also 'DQSSlDlQ IQ provide the stabilizing blades' All, shownl'figure 5, with rotating. propellers like those shown on the drawingand above des cribed.- p Q Where a plurality: ofpairs-pf wings are;em-

p a as i Fi es 62 111 th yma i e spa e at different vertical; distances 1 compared to the longitudinal axis of the fuselagegand; an;-a irplane thus constructed will have a; considerable lifting force produced by the actipnof; the :pro

pellers and can w'thergei'ore take ofi fro n the ground at a much lower space-than an ai rship provided with a single -:pair of' ;blades. Y H

Attention is calledjto the fact'thatin Figures 1 and. 2 the propellers have been; shown as provided with helical -va nes ,curved as shown in Figures 3 and 4; ;Such vanes-are believed-to be 7 preferable to straight vanes, but the helicalcon struction is not essential to successful operation. and has merely been illustrated to-show what is'at present believed to 'be the ipreferredi Q 115 struction. H

It will be observed;from'fFlsllresjll t at the auxiliary ,propellersyare; frustoconical i shape, tapering outwardly. This shapeiiidhe, primarily, to the .fact that the, ordina y airplane wings are thicker nearer theirifuselagerthanjtowards their ends and the propellers ,have. been constructed so :as toficonform :tothelshape of f the Wings.

In the present construction the arcuate 2| has been shown as extending along-:thelentire length of the propellers:and'movable as a unit (through the, action. oftherack and; pinion mechanism illustrated in Figure';4-:l.;;Atrtimes it F m t e b d s rirt n t w l a age a an a p n rovided w h;a -i1iary;vanes as h w nd ess ibe yee. tel? @1141? a;

Speed than a simila air lane nqiili r n' mary P lers, a f lh ,l i'f l' i yji l QQP E able lifting force, or the airship may tak olf with a greater load than an airplane not so structed and equipped.-

V 1 It is tobeLundrstood thatitheiinverltionhas been illustrated in a timer less. diagrammatic manner as the exact size and shape ofthe'plane,

the degree of taper of the auxiliary propellers, and the pitch of the blades can be varied to obtain the best results. When the pitch is decided it may be possible to make the propellers of double or triple pitch. But for the purpose of illustration, the long pitch has been selected.

Where the auxiliary propellers are provided on airplanes having motors attached to the blades, the auxiliary propellers maybe made in sections position on both sides of the motor mounting.

In Fig. 8 a propeller of slightly modified form has been shown. In this embodiment the blades Ila are of opposite pitch.

In Fig. 9 a further modification has been shown in which the propeller is oscillated instead of rotated. The power for oscillating the propeller is supplied by a crank 4| that transmits it to the propeller by means of a connecting rod 42.

Having described the invention what is claimed as new is:

An. airplane wing having an elongated recess in its leading edge, an elongated propeller provided with radial vanes mounted in the recess for rotation about an axis substantially parallel with the longitudinal axis of the wing, the upper surface or the wing having a longitudinally extending opening positioned adjacent the center line of the wing, the opening being in communication with the recess, whereby when the propeller is rotated, air will flow between the recess and the slot in the top of the wing and means for changing the area of the propeller exposure at the front of the recess.

DAVID W. MAIN. 

